Nutritional status and intestinal parasitism determinants of cognitive performance among secondary school students in South-East Nigeria

<h2>Summary</h2> Adolescents represent a critical population in public health research because their well-being has significant implications for future societal outcomes. This study focuses on the nutritional status and intestinal parasitism determinants of cognitive performance among secondary school students in South-East Nigeria. A cross-sectional design was used involving 481 secondary school students in five states in southeastern Nigeria. The sample included both middle and upper secondary school students from different socioeconomic backgrounds and school types. Data collection included administration of a comprehensive questionnaire, taking anthropometric measurements, assessing nutritional status using WHO-recommended Z-scores, and assessing cognitive performance through continuous assessment tests. The parasites were identified by their morphology with reference to the Cheesbrough parasitological manual. Statistical analysis was performed using chi-square tests and Quantitative Parasitological Software version 3.0. The results showed a prevalence rate of 46.4% for intestinal parasites, with Ascaris lumbricoides being the most common (50.5%). The association between intestinal parasites and cognitive performance was significant in students infected with <i>Ascaris lumbricoides</i> (50.2), hookworm (52.5), <i>Hymenolepis nana</i> (45.5) and co-infection with Ascaris hookworm (41.2) who had extremely low IQs. Assessment of nutritional status revealed that 21.2% of students were malnourished, and assessment of cognitive performance revealed a significant association between age (<i>P</i> = 0.00164) and gender (<i>P</i> = 0.000891) with IQ categories. Among the age groups, 16–18 year olds had the highest scores at 41.18% and fell under ∖"Extremely Low IQ∖", the age group > 19 was below ∖"Borderline∖" at 50%, a higher percentage of men were under ∖" "Borderline IQ" (47.27%), while a larger proportion of women were classified as "extremely low" (29.91%). The students' eating habits showed that 75.5% reported regular daily food consumption, while 24.5% had irregular eating habits. Most students (67.5%) had normal nutritional status (−2 ≤ Z ≤+1), with males (65%) slightly outnumbering females (35%), and the highest prevalence among 16–18-year-olds (36%). Overweight students (+1 < Z ≤ +2) comprised 15%, with a similar prevalence among males (22%) and females (15%), and the highest prevalence also in the 16–18-year age group (36%). The relationship between dietary habits and cognitive performance revealed that regular meals per day had a statistically significant association with cognitive performance (<i>P</i> = 0.007), frequency of consumption of fruits (<i>P</i> = 0.0378), fried foods (<i>P</i> = 0.028) and of daily water intake (<i>P</i> = 0.005) also showed significant relationships with cognitive output. These results provide valuable insights into the health and well-being of secondary school students in southeastern Nigeria and highlight the complex interplay between dietary habits, nutritional status and cognitive performance within this critical population.